The invention concerns a device in fuel tanks, preferably for vehicles, the tank being provided with a mouth socket to which a filler tube is connected.
Previously, fuel tanks for vehicles within the car industry were made from deep-drawn, lead-covered sheet metal. In accordance with prior-art technology, an upper and a lower section are welded together and the tank thus formed is provided with a socket to which a filler tube is in turn connected. In order to prevent leakages from arising at the socket mouth, as may be caused by vibrations when the vehicle is running, a rubber hose is inserted between the socket and the filler tube and attached to said components with the aid of hose clamps. In particularly exposed positions reinforced rubber hoses are usually used.
In later years, synthetic resin tanks have come into use as they are now capable of satisfying the strength and security requirements on fuel tanks. However, the technology used in the manufacture of sheet metal tanks as concerns the interconnection between the socket and the filler tube has been adopted also for synthetic resin tanks. Thus, the socket, now manufactured from blow-moulded synthetic resin, is connected to the filler tube by means of a rubber hose and hose clamps. The joint between the tank and the filler tube is, however, a weak link. The rubber hose ages more rapidly than the rest of the components, particularly when used in positions where, during vehicle running it is exposed to sprays of water mixed with sand and salt from the roadway. This increases largely the risks for leakages caused by cracks in the tube, and also increases the risks for rupture of the tube, which could easily occur in the event of a collision. Obviously, fuel leakages constitute serious fire hazards.